for plotting is it better to use 4c/8t or 6c/6t ?
More cores and threads is always better than less, when it comes to plotting.
Oh wait I misread your question a bit. Yes “real” cores are better than threads. I would say a thread is like sort of half a core, almost.
For acceptable performance plotting minimum
4c/8t = 2t-4 tasks or 4t-2 tasks
6c/6t = 2t-3 tasks
better to have more threads in my opinion